Valve controlled divided chamber internal combustion engine

ABSTRACT

Engine ( 110 ) has a plurality of combustion chambers, each of which is divided into an ignition chamber ( 114 ) and a fist combustion chamber ( 130 ). The chambers ( 114  and  130 ) awe linked by a transfer tube ( 150 ) defining a passageway ( 152 ) facilitating communication between the ignition chamber ( 140 ) and the first chamber ( 130 ). A valve ( 154 ) is prod for selectively opening and closing the passage ( 152 ). Tube ( 150 ) is provided with an opening ( 164 ) intermediate of its length allowing fuel to be injected via a fuel injector ( 138 ) into the passage ( 150 ). In a first stage of a compression stroke of a piston of the engine ( 110 ), a first volume of fuel is injected via injector ( 138 ) through opening ( 164 ) Into the passage ( 150 ). At this time, the valve ( 154 ) is in the open position so that the fuel together with air is swept into the chamber ( 144 ). In a second phase of the compression stroke the valve ( 154 ) is closed isolating the chamber ( 144 ) from the chamber ( 130 ). A second volume of fuel is also injected by the injector ( 138 ) into the passage ( 152 ). During a third phase of the compression stroke a spark plug ( 148 ) is operated to produce a spark to commence combustion of the fuel and air within the chamber ( 144 ). During a fourth phase of the compression stroke, valve ( 154 ) is rapidly opened allowing burning fuel and air to pass from chamber ( 144 ) into the passage ( 152 ) where it mixes with and causes limited combustion of the fuel within the passage ( 152 ). The products therefrom are then ejected at sonic speed through opening ( 162 ) of the tube ( 150 ) into the first combustion chamber ( 130 ) where it mixes with the air to complete combustion.

FIELD OF THE INVENTION

The present invention relates to a valve controlled divided chamberinternal combustion engine, and an associated method for operating thesame.

BACKGROUND OF THE INVENTION

In general terms, a valve controlled divided chamber internal combustionengine is an internal combustion engine having one or more combustionchambers where each combustion chamber is in effect divided into a firstcombustion chamber and an ignition chamber. The first combustion chamberand the ignition chamber communicate with each other via a passage whichis selectively opened and closed by a valve.

In such known valve controlled divided chamber internal combustionengines, two separate fuel injectors are required, namely one forinjecting fuel directly into the first combustion chamber and a secondfor injecting fuel directly into the ignition chamber. The engine isoperated so that initially fuel is injected into the ignition chamberand ignited by a spark while the valve is closed, blocking fluidcommunication between the first combustion chamber and the ignitionchamber. As a result of the valve being closed, combustion pressurewithin the ignition chamber rises rapidly. As a piston within a cylinderdefining the first combustion chamber reaches top dead centre, the valveis opened allowing combustion products (which may be considered as aplasma) to flow through a passage to the first combustion chamber. Fuelis injected into the first combustion chamber and suitably timed totravel in conjunction with the plasma as it enters the first combustionchamber providing enhanced mixing, vaporisation and subsequentcombustion of the injected fuel. This type of engine facilitates thepractical use of relatively low-grade fuels and results in thermal andmechanical efficiencies which are superior to those of traditionaldiesel methods.

The present invention is a further development of the valve controlleddivided chamber internal combustion engine.

SUMMARY OF THE INVENTION

According to the present invention there is provided a valve controlledinternal combustion engine including:

-   a cavity;-   a body moveable within said cavity, said cavity and moveable body    together defining a first combustion chamber;-   an ignition cell defining an ignition chamber and provided with a    transfer tube extending from said ignition chamber to said first    combustion chamber, said transfer tube communicating via a first    opening at one end with said ignition chamber, communicating via a    second opening at an opposite end with said first combustion    chamber, and provided with a third opening intermediate said first    and second openings;-   a fuel injector disposed to inject fuel into said transfer tube    through said third opening;-   a valve moveable between a first position where said valve provides    a high impedance to fluid flow through said first opening and a    second position where said valve provides substantially unimpeded    fluid flow through said first opening; and,-   ignition means for igniting a fuel/air mixture in said ignition    chamber.

Preferably said second opening includes a jet or orifice.

Preferably said jet orifice is one of a plurality of jet orifices.

Preferably said fuel injector injects a first volume of fuel and asecond volume of fuel into said transfer tube at different times duringa compression stroke of said body.

Preferably during a first phase of a compression stoke of said body saidvalve is moved to said second position and said injector injects saidfirst volume of fuel whereby said first volume of fuel together with airpresent in said cylinder flows through said transfer tube into saidignition chamber.

Preferably during a subsequent second phase of said compression strokeduring and after injection of said second volume of fuel said valve ismoved to said first position.

Preferably during a subsequent third phase of said compression strokesaid ignition means is operated to ignite said fuel in said ignitionchamber to produce an ignited fuel/air mixture.

Preferably during a subsequent fourth phase of said compression strokesaid valve is moved to said second position whereby said ignitedfuel/air mixture together with said second volume of fuel is injectedinto said first combustion chamber via said transfer tube.

Preferably said engine includes an air gap surrounding at least a lengthof said transfer tube.

Preferably said ignited fuel/air mixture is ejected from said transfertube through said second opening at a sonic speed.

Preferably when the body is a reciprocating piston (ie the engine is areciprocating piston engine) said first phase of said compression strokeis from commencement of said compression stroke up to 25° before topdead centre.

Preferably said second phase of said compression stroke is between 25°to 15° before top dead centre.

Preferably said third phase of said compression stroke is between 15°before top dead centre to just prior to top dead centre.

Preferably said fourth phase of said compression stroke is atapproximately top dead centre.

Preferably said piston has a head and said first combustion chamberincludes a recess formed in said piston head.

Preferably said transfer tube extends into said recess when said pistonis at top dead centre.

Preferably said recess is shaped, and said transfer tube is positionedso that ignited fuel/air mixture emanating from said second opening isdivided into two flows which rotate in opposite directions

According to the present invention there is provided a method ofoperating en engine having a first combustion chamber defined in part bya moving body retained in a cavity, an ignition chamber, a transfer tubeproviding fluid communication between said first combustion chamber andsaid ignition chamber, a fuel injector for injecting fuel into saidtransfer tube, a spark plug arranged to produce a spark for ignitingfuel in said ignition chamber, and a valve moveable between a firstposition where said valve provides a high impedance to fluid flowbetween said ignition chamber and said combustion chamber, and a secondposition where said valve provides substantially unimpeded fluid flowbetween said first combustion chamber and said ignition chamber, saidmethod including the steps of:

-   during a first phase of a compression stroke of said body, placing    said valve in said second position and operating said fuel injector    to inject a first volume of fuel into said transfer tube whereby    said fuel together with air in said first combustion dumber is    forced into said ignition chamber by action of said body.

Preferably said method includes the step of:

-   during a subsequent second phase of said compression stroke, moving    said valve to said first position and operating said fuel injector    to inject a second volume of fuel into said transfer tube.

Preferably said method includes the step of

-   during a third phase of said compression stroke, causing said spark    plug to generate a spark for igniting said fuel and air within said    ignition chamber to create an ignited fuel/air mixture.

Preferably said method includes the step of:

-   -   during a fourth phase of said compression stroke, moving said        valve to said second position whereby said ignited fuel/air        mixture is injected into said transfer tube to mix with said        second volume of fuel and subsequently sweep said second volume        of fuel into said first combustion chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described by way ofexample only with reference to the accompanying drawings in which:

FIG. 1 is a schematic representation of a prior art valve controlleddivided chamber internal combustion engine;

FIG. 2 is a schematic representation of an embodiment of a valvecontrolled divided chamber internal combustion engine;

FIG. 3 is a plan view of a crown of a piston incorporated in theembodiment depicted in FIG. 2;

FIG. 4 is a plan view of the crown of an alternate embodiment of apiston incorporated in an embodiment of the present invention;

FIG. 5A is a plan view of the crown of a further alternate pistonincorporated in the engine;

FIG. 5B is a view of section A of the crown shown in FIG. 5A; and,

FIG. 5C is a view of section B of the crown shown in FIG. 5A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 depicts schematically a prior art valve controlled dividedchamber internal combustion engine 10. Engine 10 includes an engineblock 12 which is machined to define a plurality of cavities in the formof cylinders 14 (only one shown) each of which houses a moveable body inthe form of a reciprocating piston 16. A cylinder head 18 is bolted tothe block 12 with a gasket 20 disposed between in order to provide aseal in a conventional manner. The head 18 provides communication withexhaust and intake manifolds as well as housing conventional inlet andexhaust valves 22, a rocker assembly 24 and camshaft 26. The rockerassembly 24 is closed by rocker cover 28.

A first or main combustion chamber 30 is formed in engine 10 between anupper surface 32 of the crown 34 of piston 16 which is provided with arecess or depression 35 and an upper part of the cylinder 14 bound by afacing surface 36 of the head 18. A fuel injector 38 is screwed into thehead 18 in a conventional manner to direct a spray of fuel into thefirst combustion chamber 30.

An ignition cell 40 is coupled to the head 18 and acts to provide anignition source for the fuel injected by the injector 38. The ignitioncell 40 includes a housing 42 which defines an ignition chamber 44. Afurther fuel injector 46 and a spark plug 48 are received by and coupledto the housing 42 for delivering fuel and ignition spark respectively tothe ignition chamber 44. A the 50 extends from the ignition chamber 44and provides a passageway 52 which facilitates fluid communicationbetween the first combustion chamber 30 and the ignition chamber 44.

A valve 54 within the housing 42 selectively opens and closes a throat56 of passageway 52 adjacent the ignition chamber 44. The valve 54includes a valve stem 58 having a head 60 at a distal end which is sedessentially complementary to the shape of the throat 56 and moveablebetween the first position where it provides a high impedance to theflow of fluid through the throat 56 and a second retted position whereit allows a substantially unimpeded flow of fluid through the throat 56.The valve stem 58 is driven by a scotch yoke drive 61.

Engine 10 operates as follows. Following commencement of the compressionstroke of the piston 16, the valve 54 is in its second position where itallows the flow of air being compressed by the upward movement of thepiston 16 to flow through the passage 52 and t 56 into the ignitionchamber 44. At about 25° before top dead centre (TDC) the valve 54 isclosed limiting any further substantive increase in air pressure withinthe ignition chamber 44. The timing of the closing of valve 54 resultsin a compression level within the ignition cell 44 of approximatelybetween 8:1 and 10:1. This would be less than the maximum compression inthe first combustion chamber 30 which would typically be in the order of14:1 to 15:1.

Fuel is then injected via the injector 46 into the ignition chamber 44.The fuel is vaporised by the compression heat and mixed with air withinthe chamber 44 to form a homogeneous fuel/air mix that it is typicallyrelatively rich in fuel but well within the reliable spark ignitionmixture range. Such a rich mixture enhances the ignition qualities ofthe resulting ignition cell combustion products (which may be consideredas a plasma) and injected to enhance the combustion occurring in the fitchamber 30.

During a next phase or stage of the compression cycle, the spark plug 48is operated to produce a spark to cause combustion of the fuel/airmixture within the ignition chamber 44. As a result of the combustion,the pressure within the ignition chamber 44 rapidly rises to exceed themaximum pressure within the first combustion chamber 30 when the piston16 is at TDC.

At or just prior to TDC, the injector 38 injects a volume of fuel intothe first combustion chamber 30. The valve 54 is also moved to itssecond (opened) position to provide substantially unimpeded fluidcommunication between the ignition chamber 44 and the passage 52. As aresult of the pressure differential the ignited fuel/air mixture fromthe ignition chamber 44 flows through the throat 56 and passage 52 intothe first combustion chamber 30 where it vaporises, mixes with, andcauses combustion of the fuel injected into the, chamber 30 via the fuelinjector 38.

An embodiment of the present invention is depicted in FIG. 2 in whichthe reference numbers used to describe the prior art embodiment shown inFIG. 1 with the inclusion of a preceding number one (1), are used todenote the same or similar features.

An embodiment of the valve controlled divided chamber internalcombustion engine 110 in accordance with the present invention includesmany components which arm the same or quite similar to those of thefirst embodiment including the engine block 112, cylinder 114, piston116, head 118, gasket 120, valves 122, rocker assembly 124, camshaft 126and rocker cover 128. The differences between the present embodiment ofthe engine 110 and the prior art engine 10 can be summarised as follows.

In the present embodiment 110 requires only one fuel injector 138. Thefuel injector 138 is mounted in the head 118 but at differentorientation in comparison with the prior art In the present embodimentof the engine 110, the injector 138 is mounted so as to direct the fuelinto the passageway 152 at a location intermediate the length of thetube 150. As described in greater detail below, the injector 138 isoperated twice during the compression stroke to provide fuel to theignition chamber 114 and the first combustion chamber 130. As in theprior art the piston 116 of engine 110 is provided with a recess 135 inits crown 134. The tube 150 of the ignition cell 140 extends beyondsurface 136 of the head 118 so as to partly extend into the recess 135when the piston 116 is at top dead centre. With the throat 156 of thepassage 52 being considered as a first opting of the tube 150, a secondopening 162 is formed at a distal end of the tube 150 opening into therecess 135. The second opening 162 is shaped or otherwise configured asa jet orifice. A third opening 164 is formed in the tube 150intermediate the first and second openings 156, 162 and juxtaposedrelative to the injector 138 so that fuel injected via the injector 138enters the passageway 152 through the opening 164. It will also be seenthat there is an air gap 166 between an outside surface of a lowerlength of the tube 150 and a hole 168 in the head 118 through which thetube 150 extends. The purpose of the air gap 168 is to thermally isolatethe passage 152 from the normal cooling jacket/cooling system of theengine 110. The surface 136 of the head 118 in the region of the tube150 is also substantially flatter that the surface 36 in the prior artengine 10.

As with the prior art engine 10, the valve 154 in this embodiment isdriven by a scotch yoke drive 161.

The operation of the engine 111 will now be described.

It will be appreciated that prior to the commencement of its compressionstroke, the piston 116 would have been moving through an inductionstroke drawing fresh air into the cylinder 116 for use during the nextpower stroke. As the compression stroke of the piston 116 commences, theair previously inducted into the cylinder 116 is compressed. During aninitial phase of the compression stroke, the valve 154 is moved to itssecond (or opened) position where the valve head 160 is spaced from thethroat 156 allowing fluid communication between the first combustionchamber 130 and the ignition chamber 144. Due to the upward motion ofthe piston 116, compressed air is forced up the passageway 152 into theignition chamber 144. During this phase, a first volume of fuel,typically a third of the fuel volume that would generally be required tomaintain engine idle with the same cubic capacity conventional gasolineengine, is injected into the tube 150 via the opening 164. This fuel iseffectively swept into the ignition chamber 144 by the compressed airflowing into the ignition chamber 144.

During a second subsequent phase of the compression stroke of the piston114, typically commencing at about 25° before top dead centre (BTDC) thevalve 154 is moved to its first (or closed) position where it moves intothe throat 156 providing high impedance to the flow of fluid through thethroat 156. The head 160 of the valve 154 and the throat 156 arerelatively configured, and the valve 154 operated so that it does notphysically contact the throat 156 or other parts of the tube 150 when inthe first or closed position. By closing the valve 154 at about 25° BTDCthe compression ratio within the ignition channel 144 is typicallybetween 8:1 and 10:1. However the timing of the closure of the valve 154can be varied to control the compression ratio within the ignitionchamber 144.

Also during this second phase of the compression stroke, the fuelinjector 138 is again operated to inject a second volume of fuel intothe passageway 152 via the opening 166 in the tube 150. Due to themotion of the piston 166, and the valve 154 being in its second orclosed position, the second volume of fuel is by and large held withinthe passage 152. Due to the existence of the air gap 166 the tube 150would generally be hotter than the surrounding head 118 as it is nowthermally isolated by the air gap from the conventional coolingjacket/system. This additional heat assists in vaporising the secondvolume of injected fuel. The vaporising process is further assisted bythe intermixing of hot compressed air being injected into the passageway152 as the piston 116 moves towards TDC. This forms a very fuel richmixture within the passage 152.

It will further be appreciated that up to TDC the rich fuel vapourwithin the passage 152 will be continually fed with highly heatedcompressed air entering through the angled jet orifice 162.

During a subsequent third phase of the compression stroke of piston 116,typically starting at around 15° BTDC the spark plug 148 is operated toproduce a spark to commence combustion of the fuel/air mixture withinthe ignition chamber 144. As the fuel/air mixture is combusting, thepressure within the ignition chamber 144 rises rapidly and wouldtypically greatly exceed the maximum compression ratio in the firstignition chamber 130 when the piston 116 is at TDC.

During a subsequent fourth phase of the compression stroke, typically ator just before TDC the valve 154 is very rapidly moved to its second(ie, open) position and back to the closed position Consequently, theignited fuel/air mixture from the ignition chamber 144 exits the throat156 at high velocity and flows into the passageway 152. Due to therelatively small volume of the passageway 152 and the amount of fuelpresent, the resulting mixture will be very rich and outside theexplosive range. The combustion products from the ignition chamber 144will combine intimately with the fuel vapour in the passageway 152,subsequently raising the temperature to a level well above theself-ignition point of all naturally occurring liquid hydrocarbon fuels.Accordingly the fuel injected into the passageway 152 commencescombustion thereby forming a richer secondary plasma which subsequentlyflows at a sonic velocity through the jet orifice 162 into the maincombustion chamber where it mixes with oxygen in order to complete thecombustion process. Notwithstanding that the plasma enters thecombustion chamber 130 at a sonic velocity, the oxygenation of theplasma will require a period of time, thus avoiding uncontrolled heatrelease and creating sound combustion.

The process of providing a burning plasma at sonic velocity into thefirst combustion chamber 130 is known as Sonic Plasma EnhancedCombustion (SPEC). The incorporation of this process provides theability to start the main combustion in the first combustion chamber 130at TDC and to perform fast but controlled combustion, and is at the sametime less sensitive, as combustion pressure rise now occurs in the maincombustion chamber which is staring to expand rapidly in a sympatheticmanner as the piston 116 commences its power stroke.

The size of the jet orifice 162 may be used to control transfer ofplasma from the passageway 152 into the first combustion chamber 130thereby providing a mechanism for controlling the rate of combustionwithin the chamber 130. At lower pressure, gas flow volume through anorifice is near proportional to any increase in pressure. However, oncegas pressure reaches about 147 psi sonic velocity is reached, thisbrings into play the characteristics of sonic turbulent flow at theorifice. Once this turbulence occurs it forms a flow restriction, suchthat in order to increase the flow volume in unit time, it requires verysubstantial pressure levels way beyond that obtainable by suchcombustion method in order to bypass the effects of the restrictingturbulent flow across the orifice.

Consequently, this characteristic forms an ideal method of controllingthe volume level that can be passed in unit time by a given orificediameter. The selected size orifice flow volume remains unaffected bypressure levels once above approximately 147 psi. This method of controlover the rate at which the plasma enters the first combustion chamber130 dictates the availability of the plasma's rich fuel load, and hencethe rate of the fuel's heat release when combining with the compressedair in combustion chamber 130.

Thus the main combustion rate can be controlled in a relatively simpleway by using the volume of flow and a suitable design of the orifice ororifices to reach this objective. Sonic velocity equates to a speed ofapproximately 330 mm per millisecond.

This speed is near ideal as it is fast and affords simple methods toeither speed up or slow down the combustion process.

The combustion proms within the first combustion chamber 130 may also becontrolled or effected to some extent by the configuration of the recess135 in the piston crown 134.

As depicted in FIG. 3, the recess 135 maybe formed into two sub-recessesor cavities 168 and 170 which are separated by a dividing ridge 172extending from the crown 134 to divide the plasma stream ejected fromthe orifice 162 into two separate counter-rotating vortexes king asupply of oxygen for combustion Such action creates a fat but controlledcombustion as the fuel-rich plasma will take a nite time to seek out itsrequired quota of oxygen in order to complete combustion. The plasmavortexes are also augmented by squish at the flat piston face as the airis driven inwards due to its entrapment and as the piston 116 approachesthe cylinder head surface 132. However, this squish action may be usedin a more beneficial way by making the squish action area more uniformand the combustion chamber configured to complement the production ofthe squish turbulence.

FIG. 4 illustrates an alternate configuration of the tube 152, pistoncrown 134 and recess 135. In this embodiment, the recess 135 isessentially a single circular depression in the crown 134 and the tube150 or more particularly at least the jet orifice 162 is positioned soas to direct plasma parallel to a diameter of the piston crown butoffset from the piston centre. This creates a plasma swirl or vortex inone direction only in the combustion chamber 130. This will have theeffect of reducing the combustion speed, however, due to the onedirection the turbulence pattern life will be extended and consequentlymay provide improved air utilisation.

FIGS. 5A-5C illustrate yet a further configuration of the piston crown134 and recesses 135. Here, the jet orifice 162 is aligned along adiameter of the piston crown 134 and offset from the centre of thecrown. The recess 135 is again divided into sub-cavities 168 and 170 toproduce two counter-rotating plasma vortices. The surface 136 of thecrown 134 in the recess 135 has a conical type profile with an apex 174of the conical profile being raised relative to the base so that itforms the closest point of the surface 136 within the recess 135 to thecylinder head 118. This profile of piston crown produces doughnut-shapedturbulence patterns that intersect the plasma stream as it circulatesthe outer rim of the combustion chamber 130. This air mixing actionenhances the combustion process and its rate automatically as enginespeed is increased, and provides sound level of air utilisation.

It is believed that the above embodiments of the present invention mayprovide the following benefits and enhancements over the prior art

-   -   Requires only one fuel injector for each engine cylinder        reducing cost and improving reliability    -   When only small fuel volumes are passed through a fuel injector        as in the prior art depicted in FIG. 1, it does not have as        sound a self-cleaning or cooling action as present injector 138        which also handles the full load fuel volumes.    -   By injecting the ignition cell fuel into the thermally insulated        tube 150, improved vaporisation and mixture preparation is        obtained for the ignition cell.    -   Injection of the fuel into the ignition cell air supply will        take full advantage of the fuel's latent heat of evaporation,        thus providing improved cooling to the control valve.    -   This technology suits the use of modern electronically        controlled common rail high pressure fuel supply systems, using        piezo or magneto restrictive controlled fuel injectors.    -   Current electronically controlled fuel supply systems can be        used with this single CAV micro injector approach, as the        individual pumps both incorporate one way fuel delivery valves        that will allow twin deliveries into a common pipe.    -   This method allows earlier introduction and preparation of the        main fuel volume in the transfer tube 150/passage 152 without        any risk of fuel being able to gain early entry into the main        combustion chamber 130.    -   By confining the main fuel as a conditioned vapor in the        insulated tube 150/passage 152, if the main fuel volume is at a        minimum or minimum volume, this entrapped fuel cannot avoid the        thermal and pressure energy of the ignition cells sonic plasma    -   The fuel in the passage must exit via the passage jet orifice        162 which is subjected to sonic turbulent flow characteristics,        consequently if under start up conditions some fuel was not        fully vaporized, the jet's turbulent flow will break-up any        remain fuel down to a very fine level.    -   This main fuel preparation method is simpler and of much lower        cost, than cut direct fuel injection methods aimed at tiny        droplet size by using ultra high pressure fuel injection        systems.    -   Sonic Plasma Enhanced Combustion (SPEC) reduces the fuel down to        a molecular level and also heats it above its self ignition        point, this is achieved prior to its high velocity introduction        into the main combustion chamber air volume.    -   With the fuel super heated and divided into its individual        molecules, it is in its optimum form to rapidly and completely        combine and combust with the airborne oxygen    -   The SPEC plasma methods main combustion process is not dependent        on flame propagation, or sensitive to the mixture strength    -   The fuel composition and characteristics have little influence        in achieving sound combustion, as such factors are completely        overridden by the mass transport at sonic speed of the fuel rich        plasma    -   The fuel rich burning plasma cannot combust in an uncontrolled        manner as its fuel molecules must seek out the required oxygen        molecules in the main chamber 130 to allow further combustion,        this action to combine with the main chamber oxygen while very        fast, it takes a predetermined time.    -   The main chamber combustion rate is also controllable by the jet        orifices dimensions, number and orientation.    -   SPEC process provides a multitude of unique solutions to a wide        range of previously unsolvable emission problems relating to        NOx, CO and HC.    -   The main cause of particulate emissions in current engines is        fuel droplets not finding adequate oxygen. The SPEC process        eliminates the main instigator by ensuring no droplets are        involved.    -   Due to the fuel versatility and preference for light end type        fuels exhibited by SPEC its wide spread introduction, would not        effect current petrol engine filet distribution or usage        patterns.    -   SPEC can also operate on current fuels until cheaper wide cut        low specification fuels are made generally available.    -   Using SPEC over the road fuel economy will be significantly        improved, while the high processing costs for current strict        specification fuels can be avoided.

As previously mentioned, a substantial benefit in an embodiment of thepresent invention is the ability to allow an engine to operate onsecondary fuels (low grade) as well as LNG and LPG. This arises due tothe conditioning of the main volume of the fuel combusted during anypower stroke. This arises due to a combination of factors including thepre-ignition of a smaller volume of fuel in the ignition cell whichprovides a plasma source for igniting the main volume of fuel; theholding of the main volume of fuel within the tube 150 for vaporisation,and the SPEC process.

Now that an embodiment of the invention has been described in detail itwill be apparent to those skilled in the relevant arts that numerousmodifications and variations may be made without departing from thebasic inventive concepts. For example, the valve 154 is described andillustrated as being driven by a scotch yoke drive. However any othertype of drive mechanism including electronically controlled mechanismsmay be used. In addition, the transfer tube 150 is depicted as beingprovided with a single jet orifice 162. However two or more jet orificescan be provided. Also, while the preferred embodiment is described inrelation to a reciprocating piston engine, embodiments may be applied toother types of combustion engines such as rotary (eg Wankel) engines. Insuch embodiments, the cavity is in the form of the engine housing andthe moveable body is in the form of a rotor, rather than a cylinder andpiston, respectively. Further, when applied to a rotary engine the tingdescribed with reference to phases of the compression stroke of thepiston will need to be converted to a corresponding rotor angularposition.

All such modifications and variations together with others that would beapparent to those skilled in the relevant arts are deemed to be withinthe scope of the present invention the nature of which is to bedetermined from the above description and the appended claims.

1. A valve controlled internal combustion engine including: a cavity; abody moveable within said cavity, said cavity and moveable body togetherdefining a first combustion chamber; an ignition cell defining anignition chamber and provided with a transfer tube extending from saidignition chamber to said first combustion chamber, said transfer tubecommunicating via a first opening at one end with said ignition chamber,communicating via a second opening at an opposite end with said firstcombustion chamber, and provided with a third opening intermediate saidfirst and second openings; a fuel injector disposed to inject fuel intosaid transfer tube through said third opening; a valve moveable betweena first position where said valve provides a high impedance to fluidflow through said first opening and a second position where said valveprovides substantially unimpeded fluid flow through said first opening;and, ignition means for igniting a fuel/air mixture in said ignitionchamber.
 2. The engine according to claim 1 wherein, said second openingincludes a jet orifice.
 3. The engine according to claim 2 wherein saidjet orifice is one of a plurality of jet orifices.
 4. The engineaccording to claim 3 wherein said fuel injector injects a first volumeof fuel and a second volume of fuel into said transfer tube at differenttimes during a compression stroke of said body.
 5. The engine accordingto claim 4 wherein during a first phase of a compression stroke of saidbody said valve is moved to said second position and said injectorinjects said first volume of fuel whereby said first volume of fueltogether with air present in said cavity flows through said transfertube into said ignition chamber.
 6. The engine according to claim 5wherein during a subsequent second phase of said compression strokeduring and after injection of said second volume of fuel said valve ismoved to said first position.
 7. The engine according to claim 6 whereinduring a subsequent third phase of said compression stroke said ignitionmeans is operated to ignite said fuel in said ignition chamber toproduce an ignited fuel/air mixture.
 8. The engine according to claim 7wherein during a subsequent fourth phase of said compression stroke saidvalve is moved to said second position and thereafter returned to saidfirst position, whereby said ignited fuel/air mixture together with saidsecond volume of fuel is injected into said first combustion chamber viasaid transfer tube.
 9. The engine according to claim 1 including an airgap surrounding at least a length of said transfer tube.
 10. The engineaccording to claim 9 wherein said ignited fuel/air mixture is ejectedfrom said transfer tube through said second opening at a sonic speed.11. The engine according to claim 8 wherein, when said body is areciprocating piston, said first phase of said compression stroke isfrom commencement of said compression stroke up to 25° before top deadcentre.
 12. The engine according to claim 11 wherein, when said body isa reciprocating piston, said second phase of said compression stroke isbetween 25′ to 150 before top dead centre.
 13. The engine according toclaim 12 wherein, when said body is a reciprocating piston, said thirdphase of said compression stroke is between 15° before top dead centreto or just prior to top dead centre.
 14. The engine according to claim13 wherein, when said body is a reciprocating piston, said fourth phaseof said compression stroke is at approximately top dead centre.
 15. Theengine according to claim 14 wherein, when said body is a reciprocatingpiston, said piston has a head and said first combustion chamberincludes a recess formed in said piston head.
 16. The engine accordingto claim 15 wherein said transfer tube extends into said recess whensaid piston is at top dead centre.
 17. The engine according to claim 14wherein said recess is shaped, and said transfer tube is positioned sothat ignited fuel/air mixture emanating from said second opening isdivided into two flows which orate in opposite directions.
 18. A methodof operating an engine having a first combustion chamber defined in partby a moving body retained in a cavity, an ignition chamber, a transfertube providing fluid communication between said first combustion chamberand said ignition chamber, a fuel injector for injecting fuel into saidtransfer tube, a spark plug arranged to product a spark for ignitingfuel in said ignition chamber, and a valve moveable between a firstposition where said valve provides a high impedance to fluid flowbetween said ignition chamber and said combustion chamber, and a secondposition where said valve provides substantially unimpeded fluid flowbetween said first combustion chamber and said ignition chamber, saidmethod including the steps of: during a first phase of a compressionstroke of said body, placing said valve in said second position andoperating said fuel injector to inject a first volume of fuel into saidtransfer tube whereby said fuel together with air in said firstcombustion chamber is forced into said ignition chamber by action ofsaid body.
 19. The method of claim 18 wherein during a subsequent secondphase of said compression stroke, moving said valve to said firstposition and operating said fuel injector to inject a second volume offuel into said transfer tube.
 20. The method of claim 19 wherein duringa third phase of said compression stroke, causing said spark plug togenerate a spark for igniting said fuel and air within said ignitionchamber to create an ignited fuel/air mixture.
 21. The method of claim20 wherein during a fourth phase of said compression stroke, moving saidvalve to said second position whereby said ignited fuel/air mixture isinjected into said transfer tube to mix with said second volume of fueland subsequently sweep said second volume of fuel into said firstcombustion chamber.
 22. An ignition cell for an internal combustionengine having a cavity, a body moveable within said cavity, said cavityand moveable body together defining a first combustion chamber, and afuel injector for injecting fuel for combustion in said engine, saidignition cell including: a housing attachable to said internalcombustion engine and defining an ignition chamber; a transfer tubeextending from said ignition chamber to said first combustion chamber,said transfer tube communicating via a first opening at one end withsaid ignition chamber, communicating via a second opening at an oppositeend with said first combustion chamber, and provided with a thirdopening intermediate said first and second openings and disposed toreceive said fuel injected by said fuel injector; and, a valve moveablebetween a first position where said valve provides a high impedance tofluid flow through said first opening and a second position where saidvalve provides substantially unimpeded fluid flow through said firstopening; and, ignition means supported by said housing for igniting afuel/air mixture in said ignition chamber.
 23. The ignition cellaccording to claim 22 wherein said second opening includes a jetorifice.
 24. The ignition cell according to claim 23 wherein during afirst phase of a compression stroke of said body, said valve is moved tosaid second position and said injector injects a first volume of fuelwhereby said first volume of fuel together with air present in saidcavity flows through said transfer tube into said ignition chamber. 25.The ignition cell according to claim 24, wherein during a subsequentsecond phase of said compression stroke during and after injection of asecond volume of fuel by said fuel injector into said third opening,said valve is moved to said first position.
 26. The ignition cellaccording to claim 25 wherein during a subsequent third phase of saidcompression stroke said ignition means is operated to ignite said fuelin said ignition chamber to produce an ignited fuel/air mixture.
 27. Theignition cell according to claim 26 wherein during a subsequent fourthphase of said compression stroke said valve is moved to said secondposition thereafter returned to said first position whereby said ignitedfuel/air mixture together with said second volume of fuel is injectedinto said first combustion chamber via said transfer tube.
 28. A valvecontrolled internal combustion engine comprising: a cavity; a bodymoveable within said cavity, said cavity and moveable body togetherdefining a first combustion chamber; an ignition cell defining anignition chamber and provided with a transfer tube extending from saidignition chamber to said first combustion chamber, said transfer tubecommunicating via a first opening at one end with said ignition chamber,communicating via a second opening at an opposite end with said firstcombustion chamber, and provided with a third opening intermediate saidfirst and second openings; a fuel injector disposed to inject fuel intosaid transfer tube through said third opening; a valve moveable betweena first position where said valve provides a high impedance to fluidflow through said first opening and a second position where said valveprovides substantially unimpeded fluid flow through said first opening;and an igniter designed to ignite a fuel/air mixture in said ignitionchamber.
 29. An ignition cell for an internal combustion engine having acavity, a body moveable within said cavity, said cavity and moveablebody together defining a first combustion chamber, and a fuel injectorfor injecting fuel for combustion in said engine, said ignition cellcomprising: a housing attachable to said internal combustion engine anddefining an ignition chamber; a transfer tube extending from saidignition chamber to said first combustion chamber, said transfer tubecommunicating via a first opening at one end with said ignition chamber,communicating via a second opening at an opposite end with said firstcombustion chamber, and provided with a third opening intermediate saidfirst and second openings and disposed to receive said fuel injected bysaid fuel injector; and a valve moveable between a first position wheresaid valve provides a high impedance to fluid flow through said firstopening and a second position where said valve provides substantiallyunimpeded fluid flow through said first opening; and, an igniter,supported by said housing, and designed to ignite a fuel/air mixture insaid ignition chamber.
 30. A method of making a valve controlledinternal combustion engine comprising: providing a cavity; providing abody moveable within said cavity, said cavity and moveable body togetherdefining a first combustion chamber; providing an ignition cell definingan ignition chamber and provided with a transfer tube extending fromsaid ignition chamber to said first combustion chamber, said transfertube communicating via a first opening at one end with said ignitionchamber, communicating via a second opening at an opposite end with saidfirst combustion chamber, and provided with a third opening intermediatesaid first and second openings; providing a fuel injector disposed toinject fuel into said transfer tube through said third opening;providing a valve moveable between a first position where said valveprovides a high impedance to fluid flow through said first opening and asecond position where said valve provides substantially unimpeded fluidflow through said first opening; and providing an igniter designed toignite a fuel/air mixture in said ignition chamber.
 31. A method ofmaking an ignition cell for an internal combustion engine having acavity, a body moveable within said cavity, said cavity and moveablebody together defining a first combustion chamber, and a fuel injectorfor injecting fuel for combustion in said engine, said methodcomprising: providing a housing attachable to said internal combustionengine and defining an ignition chamber; providing a transfer tubeextending from said ignition chamber to said first combustion chamber,said transfer tube communicating via a first opening at one end withsaid ignition chamber, communicating via a second opening at an oppositeend with said first combustion chamber, and provided with a thirdopening intermediate said first and second openings and disposed toreceive said fuel injected by said fuel injector; and providing a valvemoveable between a first position where said valve provides a highimpedance to fluid flow through said first opening and a second positionwhere said valve provides substantially unimpeded fluid flow throughsaid first opening; and, an igniter, supported by said housing, anddesigned to ignite a fuel/air mixture in said ignition chamber.